Union Banks
Union Banks is a large drowned atoll in the center of Dangerous Ground in the Spratly Islands in South China Sea, west of the Philippine coast, containing islands and reefs whose ownership remains disputed and controversial. The closest atoll is Tizard Bank, due north of Union Banks. There are only two natural islands on the rim of the reef, Sin Cowe Island and Sin Cowe East Island.
The atoll is long from Johnson South Reef in the southwest to Whitson Reef in the northeast, and up to wide. Its total area measures. The central lagoon is up to deep.
Islands and reefs comprising Union Banks
Union Banks consists of the following islands and reefs, clockwise starting in the southwest corner:Key: yellow = occupied by PRC; violet = occupied by Vietnam
| Feature | Location |
| Johnson South Reef | |
| Collins Reef/Johnson North Reef | |
| Đá Tam Trung | |
| Sin Cowe Island/Sinh Ton Island | |
| /Kennan Reef | |
| Đá Bia | |
| Hughes Reef | |
| * | |
| * | |
| Whitsun Reef/Whitson Reef | |
| Grierson Reef/Sin Cowe East Island | |
| /Higgen Reef | |
| Lansdowne Reef |